美国国家公共电台 NPR--What does the nuclear fusion breakthrough mean for the future?（在线收听）

What does the nuclear fusion breakthrough mean for the future?

Transcript

NPR's Rob Schmitz talks to Dennis Whyte of the Plasma Science and Fusion Center at MIT, about what the expected announcement about fusion energy means for climate and energy sustainability on Earth.

ROB SCHMITZ, HOST:

Let's turn now to Dr. Dennis Whyte to ask what this means for the long term. He's the director of the Plasma Science and Fusion Center at MIT. Dr. Whyte, this is being called a breakthrough in the search for limitless, clean energy. In a few words, how would you explain this to someone who knows very little about this?

DENNIS WHYTE: Right. So in fusion, what you're doing is literally fusing or pushing together these hydrogen atoms. They turn into helium. This is what happens in our sun as well, too. And when that happens, that can release large amounts of net energy. So what we've been - the achievement of this, which sounds a little bit like science fiction, that you have to achieve extremely high temperatures...

SCHMITZ: It does, yeah.

WHYTE: ...Like over 50 million degrees - has eluded us about making net energy out of any single sort of event of this. So if confirmed this morning by the secretary of energy, this is indeed a breakthrough.

SCHMITZ: Later this morning, we expect to hear scientists say that they have achieved ignition. What does that mean?

WHYTE: Right. So the definition varies slightly between the different ways that you approach fusion. But the definition that was provided by the National Academies was that for this particular approach to fusion, which uses lasers, that when the amount of fusion energy exceeded the input laser energy, then that was the definition of ignition. There's various other definitions which matter for making it economically viable.

SCHMITZ: And as I understand it, they're generating no electricity. And they are using vastly more electricity than they get out in fusion. But the lasers need a lot of electricity, right? So this experiment still took energy off the grid?

WHYTE: That's correct. I mean, to be clear, they were not even attempting to make electricity out of it.

SCHMITZ: Yeah.

WHYTE: And, in fact, this is one of the other aspects that needs to improve, is that you need to get fairly high levels of gain to make this a viable energy source, you know, to be a practical power plant. But getting over the threshold scientifically of seeing net energy is a major accomplishment because you see for the first time sort of the physical conditions of which will be required for a power plant as we extrapolate forward.

SCHMITZ: Dr. Whyte, given what we know now, how long do you estimate it'll take for scientists to be able to replicate this discovery on a broader scale so that societies can actually use this type of energy? And what steps will we need to take to do that?

WHYTE: Right. Well, the exciting thing is that this has been pursued, you know, by science, scientists around the world, including in the United States, obviously, for many decades. And we've made important progress scientifically towards this. But what's changed in the context of this, of what we think - we anticipate with this announcement, is that, indeed, the advent of a private sector in fusion also indicates about both the push and the - you know, because of climate change - and the pull that's coming from the commercial sector about getting to the point where we can actually put this on the grid. And there is a push to try to do this within the next decade. It is difficult. The technology is difficult. But these are these kinds of advances that provide hope to us that, in fact, we're on the right path.

SCHMITZ: Dennis Whyte is the director of the Plasma Science and Fusion Center at MIT. Dennis, thank you.

WHYTE: Bye.

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